The invention concerns a method and device for the separation of blood or cells of blood-forming organs, such as bone marrow, into their components and for the isolation of those components by means of centrifuging in which a source reservoir, which is connected with one or more recipient reservoirs via an outflow opening, is applied as a container for the blood or the bone marrow.
Blood consists of four components which, in order of increasing specific gravity, are: blood plasma, blood platelets, white blood cells and red blood cells. For the red blood cells further distinction is made between the old cells--the gerocytes and the newly-formed cells--the neocytes. The average lifetime of a red blood cell is approximately 90 days. "New" cells will therefore still be able to live for a relatively long time, which can be of great importance in the case of blood transfusion. The specific gravity of the red blood cells increases as they get older, so that with the aid of centrifuging it is possible to achieve a certain distribution of the red blood cells according to age. White blood cells and blood platelets-- together called `buffycoat`--constitute in total approximately 1% of the volume of normal blood. Approximately 45% of the total volume is taken up by red blood cells and after centrifuging approximately 50% of the neocytes are situated in a layer thereof, which layer comprises approximately 10% of the total outgoing volume.
In the prior art, both the components which constitute the buffy-coat and the neocytes are separated from one another according to a known procedure, and thereafter isolated from one another. For this purpose see, for example, European Pat. No. 0026417. A difficulty in this connection is the isolation of the relatively small fractions--the white cells, the platelets and the neocytes--without much loss occurring through, for example, contamination in the adjoining surfaces.
In European Pat. No. 0026417 a method is described for the separation and isolation of blood components. After separation by centrifuging the layers are successively pumped out of the source reservoir and then collected. The pumping out is done by exerting a sideways pressure on the flexible source reservoir with the aid of a pressure cushion. Liquid is then pressed out of the reservoir. A description is given of how in that way blood plasma is transferred to an adjacent recipient reservoir.
A device for separating and isolating blood components described in the above-discussed European Pat. No. 0026417 consists of a centrifuge with one or more containers mounted at a certain radial distance from the centrifugal axle which rotate together with the centrifuge during use. Each contains a source reservoir with an outflow opening which is in the main directed at the centrifugal axle, with which the reservoir is joined via an outflow pipe with one (or more) recipient reservoir(s) as a closed system. This centrifuge is equipped with a pump mechanism with which, after they have been separated, the components are pumped out of the source reservoir to the recipient reservoir(s).
In "Nature", vol. 217, page 816 et seq., a method is described with which the said disadvantage is removed, with the aid of a "continuous-flow" process. Thereby the components are both separated and isolated during centrifuging. Contamination after centrifuging does therefore not occur there.
This described process, however, also has disadvantages: the necessary supply and drain pipes with their accompanying channels and rotating seals lead to a costly and complex construction. Another disadvantage is that in one centrifugal process there can only be worked with one reservoir, which leads to a low processing capacity.